Nanoscale phase separation in manganites

We study the possibility of nanoscale phase separation in manganites in the framework of the double-exchange model. The homogeneous canted state of this model is proved to be unstable towards the formation of small ferromagnetic droplets inside an antiferromagnetic insulating matrix. For the ferromagnetic polaronic state we analyse the quantum effects related to the tails of electronic wave function and a possibility of electron hopping in the antiferromagnetic background. We find that these effects lead to the formation of the threshold for the polaronic state.